1. Field of the Invention
The present invention relates to a bistable display device, and more specifically, to a configuration of electrical ports of a bistable display device.
2. Description of Related Art
The outdoor reflective display has been widely used today. Most of such displays are used in portable devices. As a result, there has been a great demand for displays that are lightweight and small-sized and thus it is becoming more and more important to design display devices that are relatively light in weight and thin in thickness.
Traditional Liquid Crystal Displays (LCDs) such as TFT (Thin Film Transistor) LCDs have been maturely developed and shrinking of the thickness of LCDs has approached to a limit. In other words, now it is rather difficult to further shrink the thickness of the LCDs. To meet the demand for products such as electronic books and electronic paper, many companies are looking at the research and development of bistable displays, which have a great potential to be one of the mainstream types of displays in the future.
Currently the bistable display device usually has a driver IC (Integrated Circuit) that is electrically connected to external circuits. The driver IC includes a source IC and a gate IC. The bistable display device further includes a flexible printed circuit (FPC). According to different module processes or designs, bistable display devices can be divided into different types such as chip on glass (COG), tape automatic bonding (TAB), chip on film (COF) and so on. With all such different designs, there will be different positional displacement between the ICs, the electronic components and the display device. During plugging and unplugging of all kinds, damages may be made to the FPC and the substrate caused by the pulling tearing, and alignment stress. Such damage may be mechanical and/or electrical and may impair the optimal operation or the stability of the bistable display device. Especially in terms of electrical effects, the electric voltage used in bistable display device is normally higher than the voltage used in TFT LCDs (typically 3˜5 volts, 6˜8 volts maximum). If neighboring ports of the ICs in the bistable display device are separated by the same distance as in the case of a TFT LCD, when the electric potential difference between the ports is relatively large, for example, greater than or equal to 10 volts, the electrostatic interference between the ports may be quite significant, which may cause the driver IC of the bistable display device to function unstably and the image quality to be compromised. In a worse case, the material between the neighboring ports may be electrically punched through, which may in turn cause short circuits and the whole IC to be burned and damaged. This problem thus has become an important one in design of bistable display devices.